Rotary imprinter with ink wheel having temperature controlled ink pad

ABSTRACT

A marking apparatus which includes marking and inking wheels mounted individually for rotation and with the peripheries thereof in operative engagement. The marking wheel includes a rim portion having a closed loop of rubber type removably telescopically fitted over the exterior thereof. The opposite circumferential edge portions of the type loop are secured to the wheel so as to prevent the loop from becoming separated from the wheel during rotation. The means for securing the loop to the wheel is in two parts, these parts being removably secured together such that removal of one of the parts permits facile replacement of the type loop on the wheel. The inking wheel includes an annular ink-retaining pad on the periphery thereof which maintains the type on the marking wheel continuously coated with ink during marking wheel rotation. Means are provided on the inking wheel for controlling the temperature of the pad such that transfer of ink from the pad to the type is always assured.

United States Patent 1 Johnson et al.

[ 1 June 5, 1973 [54] ROTARY IMPRINTER WITH INK WHEEL HAVING TEMPERATURE CONTROLLED INK PAD [73] Assignee: Lincoln Logatype Co., Inc., Fort Wayne, Ind.

[22] Filed: Dec. 23, 1970 [21] Appl. No.1 100,879

[521 U.S. Cl. ..l0l/329,10l/35, 101/348, 101/376 [51] Int. Cl. ..B41f 13/10, B4lf 31/26 [58] FieldofSearch .1lOl/3537,8,25,32833l, l0l/375,376,348352, 101/205-209 [56] References Cited UNITED STATES PATENTS 1,683,774 9/1928 Haase ..l01/35 1,883,257 10/1932 Wood ....101/350 Primary Examiner-J. Reed Fisher Attorney-Hood, Gust, Irish, Lundy & Coffey [57] ABSTRACT A marking apparatus which includes marking and ink ing wheels mounted individually for rotation and with the peripheries thereof in operative engagement. The marking wheel includes a rim portion having a closed loop of rubber type removably telescopically fitted over the exterior thereof. The opposite circumferential edge portions of the type loop are secured to the wheel so as to prevent the loop from becoming separated from the wheel during rotation. The means for securing the loop to the wheel is in two parts, these parts being removably secured together such that removal of one of the parts permits facile replacement of the type loop on the wheel.

8 Claims, 11 Drawing Figures 1,916,661 7/1933 Flothow ..l0l/25 3,412,707 11/1968 West... ..l0l/25 X 1,949,688 3/1934 Kranz ..101/375 2,186,555 l/1940 Phillips ..101/36 2,211,794 8/1940 Rohland 101/376 2,260,364 10/1941 Case ....101/350 2,471,098 5/1949 Davies ..l01/35 I! 1 Q m, 94 "fi -g I I 124 f m m I #80 an 5 I 9L I 1:1 9 I PATENIEDJUM 5 ms 3, 736, 870 SHEET 1 OF 4 INVEN roves; LEONARD L.JOHNGON,

TENN'E MAHONEY, HARRY L... HART,

Bv Mild,

AT TORNEYS.

PATENTEDJUH 5 I975 3. 736,870 SHEET 3 OF 4 N 9 INVENTORS.

E'ONARD L.JoHNsoN,

Temms MAHONEY,

HARRY L.HAR1-,

ia A B UM,M LM*% ATTORNEYS.

PATENIEDJLm 5 I975 3,736,870

- SHEET u or a FIGJO FIGQ 5 & l

#12 f 26 I02 f INVENTORSI LEONARD l JOHNSON,

ROTARY IMPRINTER WITH INK WHEEL HAVING TEMPERATURE CONTROLLED INK PAD BACKGROUND OF THE INVENTION 1. Field of the lnvention The present invention relates to a rotary imprinter and more particularly to marking apparatus for printing codes or characters on articles, such as strips of lumber, conveyed along a given path.

2. Description of the Prior Art It is conventional to print trademarks, brand names, or other identifying codes on selected surfaces of framing or panel type lumber. Imprinting with ink in a consistent and uniform manner has not been entirely successful for reasons, among others, that below certain ambient temperatures, such as 55 F., the ink does not flow and imprint properly, and irregularities in the lumber surfaces cause improper contact between the marking wheel and the lumber surface thereby producing illegible imprinting.

In order to print consistently and legibly, it is necessary for the printing apparatus not only to be capable of proper adjustment, but also that it respond precisely to irregularities in the surface being printed such that at all times the proper printing force will be applied to the surface during printing operations. Furthermore, in order to assure proper imprinting in cold temperatures, it is necessary that the ink be maintained at a temperature which assures proper transferal to the type and onto the article.

SUMMARY OF THE INVENTION The present invention provides a marking apparatus which includes marking and inking wheels mounted with the peripheries thereof in operative engagement. The marking wheel includes a circumferential rim portion having a closed loop of rubber type removably telescopically fitted onto the exterior thereof. Means are provided for securing said loop at the opposite circumferential edges thereof to the rim portion and against radially outward dislocation there from during rotation of the marking wheel. This securing means includes means removably secured to the wheel for securing one of the edges and is so constructed that it does not interfere with telescoping the loop on and off the rim portion. The inking wheel includes an annular ink-retaining pad on the periphery thereof, and means for controlling the temperature of the pad in a range at which engagement of the pad with type on the marking wheel results in coating the type properly with ink.

It is an object of this invention to provide a marking apparatus which is capable of printing legibly on the surfaces of articles of lumber and the like as they are conveyed sequentially along a given path.

It is another object of this invention to provide a marking apparatus which may be adjusted while in operation for the purpose of obtaining a legible marking.

It is a further object of this invention to provide a marking apparatus utilizing both inking and marking wheels which may be operated at ambient temperatures at which the ink ordinarily will not transfer properly.

It is still a further object of this invention to provide a unique marking wheel capable of facile manipulation for replacing rubber type normally mounted thereon.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front perspective view of an embodiment of this invention;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is a longitudinal sectional view taken substantially along section line 4-4 of FIG. 3;

FIG. 5 is a plan view of the bifurcated frame member of the preceding figure;

FIG. 6 is a side view partly sectioned of the frame member of FIG. 5;

FIG. 7 is a view of the eccentric shaft which mounts the inking wheel assembly;

FIG. 8 is a sectional view of the heater assembly taken substantially along section line 8-8 of FIG. 4;

FIG. 9 is a rear view of the inking wheel;

FIG. 10 is a fragmentary sectional view taken substantially along line l0l0 of FIG. 3; and

FIG. 11 is a schematic diagram of the electrical circuitry used in conjunction with the heater shown in the preceding figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, which are substantially to scale, and more particularly to FIGS. 1 through 4, a bifurcated frame member 12 (shown in detail in FIGS. 5 and 6) is pivotally adjustably secured at its distal end to a rigidly mounted plate 14, the frame 12 being held against rotation by means of a clamping screw 16 which clamps a split collar 18 on the frame 12 to a pivot pin 20 fixedly secured by means of similar screws 22 against rotation with respect to the plate 14.

The opposite end portion of the frame 12 is bifurcated as shown more clearly in FIG. 5 for receiving between the fingers 22 and 24 a rigid supporting arm 26. A pivot pin 28 passing through both the supporting arm 26 and the two fingers 22 and 24 is shown for pivotally mounting the arm 26 on the frame 12.

A screw 30 threadedly received by the arm 26 enters the groove 32 in the pin 28 (see FIG. 10) to secure the pin 28 against movement endwise.

A frame 12 and arm 26 are limited for pivotal movement in one direction by means of a stop screw 34 threaded into the arm 26 and a nylon plug 36 engaged by one end of the screw 34 and projecting beyond the opposite side of the arm 26 to engage the side of the frame 12, as shown more clearly in FIG. 3. By adjusting the screw 34, the plug 36 may be moved axially to determine the extent at which the arm 26 may rotate clockwise as shown in FIG. 3 with respect to the frame 12.

Pivotal movement in the opposite direction of the arm 26 is limited by means of a screw and spring assembly which comprises an elongated screw 38 received by enlarged bore 40 in the frame 12 providing clearance therewith and another clearance bore 42 in the arm 26 to be threaded into a bearing 44 pivotally mounted in a suitable opening in the arm 26. The axis of the bearing 44 is parallel to the axis of the pin 28. Another clearance opening 46 is provided in the arm 26 to extend oppositely from the clearance opening 42 to permit threading the screw 38 through the bearing 44 to project from the opposite side thereof for adjustment purposes. A compression spring telescoped over the shank of the screw 38 and engaging the head thereof for a stop is nested in a socket 50 in the frame 12 to bear against the bottom thereof. The spring 48 thereby urges the screw 38 upwardly as viewed in FIG. 3 thereby yieldably urging the arm 26 clockwise about the pivot 28 and contacting the stop in 36 with the frame 12. counterclockwise movement of the arm 26 is resisted by the spring 48 such that between the stop assembly 34, 36 and the spring assembly 38, 48, the arm 26 is positioned statically with respect to the frame 12. Any counterclockwise movement of the arm 26 is accommodated by the spring assembly 38, 48 by reason of the clearance openings 40, 42 and 46 as well as the pivot bearing 44 which will swing slightly in the arm 26 as the latter moves.

A marking wheel assembly comprises a wheel 52 rotatably mounted on a shaft 54 fixedly secured against rotation in the distal end of the arm 26. This end is split as indicated by the numeral 57 and provided with a clamping screw 58 whereby the shaft 54 may be adjusted axially.

The wheel 52 includes a cylindrical arbor 56 rotatably mounted on the shaft 54 by means of two bearing assemblies 59 as shown. At the rear of the arbor 56 is provided a flat side 60 having a circumferential rib 62 provided with an inwardly opening annular groove 64 as shown.

Telescopically received by the arbor 56 is a hub 66 having a knob 68 on the outer end thereof, another wheel side 70 extending radially outwardly from the hub 66 as shown. An inner portion of the hub 66, as indicated by the numeral 72, of tubular shape, telescopes over an enlarged diameter portion 74 on the arbor 56 as shown. The enlarged portion of the arbor is provided with an annular groove 76 which receives a detent spring 78 in the form of a helical wire spring joined at the ends to provide a loop. A portion of the spring 78 protrudes radially beyond the groove 76 to fit into a shallow annular groove 80 in the hub portion 72 removably to secure the hub 66 to the arbor 56. A suitable detent attachment like the one just described is disclosed in Harry L. Hart application Ser. No. 874,827, filed Nov. 7, 1969, and entitled Spring Detent Hub. Another detent spring arrangement that may be used instead is disclosed in U.S. Pat. No. 3,327,624, Millard B. Beaver, inventor.

Relative rotation between the arbor 56 and hub 66 is prevented by means of an axially extending slot 82 in the outer end of the arbor 56 which receives the protruding end of a radially extending pin 84 first fitted in the knob 68 as shown. The fit between the pin and slot 82, 84 is loose enough to permit facile telescoping of the hub 66 over the arbor 56.

An annular groove 86 of the same shape and size as the groove 64 faces the latter as shown. A cylindrical portion 88 on the flange 70 provides a rim for the wheel which also defines the inner radial extent of the two grooves 64, 86.

A circular loop 90 of type made of soft rubber of' cross section as shown in FIG. 4 of the drawings is fitted into the groove 64, 86 as shown with the base thereof in engagement with the outer surface of the rim 88. The

loop 90 has an inner diameter substantially the same as the outer diameter of the rim 88, but otherwise is of such size that intimately engages the rim 88 without undue stretching thereof.

The type loop 90 is installed on the wheel 52 in the following manner. The wheel section 68, is removed from the other wheel section 56, 60 by grasping the knob 68 and withdrawing the section 68, 70 from the arbor 56. A type loop is telescoped over the rim 88 until the circumferential edge thereof fits snugly into the groove 86. In a preferred embodiment, this circumferential edge of the type loop is made to substantially the same size and shape as the groove 86 to fit snugly therein.

The wheel section 68, 70 is next telescoped into assembled position with the other wheel section 56, 60 such that the opposite circumferential edge of the type loop made to the same size and shape as the groove 64 snugly fits into the latter. With this operation, the type loop 90 is securely mounted into position.

The central portion of the type loop 90, as indicated by the numeral 92, contains the type characters, these characters being numbers, letters or symbols, and axially outwardly therefrom as indicated by the numeral 94 are two coaxial annular ridges which project radially outwardly to an extent about flush with the outer periphery of the characters 92. These annular ribs 94, as will become apparent from the description that later follows, serve as drive rims for imparting rotation to the wheel 52.

An inking-roll device, indicated generally by the reference numeral 96, is rotatably mounted on the arm 26 by means of an eccentric shaft indicated generally by the numeral 98 (see FIGS. 3 and 10). This eccentric shaft 98 has a journaled portion 100 rotatable in the arm 26 provided with a circumferential groove 102 into which is fitted a nylon ball 104 engaged by the distal end of a set screw 106 threaded into the arm 26. The nylon ball 104 provides a smooth, rubbing engagement with the groove 102. The screw 106 is adjusted to bear against the groove 102 with a sufficient force to permit the shaft 96 to be forcefully rotationally adjusted manually while the apparatus is in operation. This adjustment is provided by means of a laterally extending handling 108 on the outer end of the shaft 98 as shown more clearly in FIGS. 2 and 4.

An eccentric shaft extension 110 on shaft 98 (see FIGS. 4, 7 and 10) extends beyond the opposite side of the arm 26 and in parallelism with the pivot pin 28. On the eccentric extension 110 is rotatably mounted an inking wheel indicated generally by the numeral 96. This inking wheel is constructed essentially the same as the marking wheel 52 but with different dimensions and parts to adapt the same for use in inking the type loop 90. More specifically, the wheel 96 includes an arbor 112 rotatably mounted on the shaft extension 110 by means of suitable bearings 114. Telescoped over the arbor 112 is a hub 116 having one side 118 of the wheel extending radially therebeyond as shown. The arbor 1 12 at the rear end thereof has the other side of the wheel denoted by the numeral 120 thereon as shown, theperipheral portions of these sides providing a square-shaped recess 124 having as the bottom thereof the wheel rim 126. This wheel rim 126 is of cylindrical shape integral with the wheel side 118.

A detent spring device 128 secures the two wheel sections together the same as just described in connection with the marking wheel 52.

The outer peripheral portions of the recess 124 are provided with inwardly extending lips 130 which serve to retain an annular inking pad 132 against radially outward dislodgement. The pad 132 is of the same design as that disclosed in US. Pat. No. 3,327,624 or as disclosed in U.S. Pat. No. 2,777,824. The pad is so constructed as to have pores filled with liquid ink which exudes to the outer peripheral surface by the process of osmosis. The liquid on the surface is replenished by the liquid inside as it distributes itself throughout the plastic. Quite obviously, once the supply of ink is exhausted, the pad must be replaced, this being simply accomplished by grasping the hub 116 and withdrawing it from the wheel section 112, 120 and replacing the exhausted pad 132 with a new one. With the new pad so installed, the wheel section 118 is reinstalled on the arbor 112 as previously described.

An inking wheel device of substantially the same design is disclosed and claimed in U.S. Pat. No. 3,327,624.

Radial adjustment of the pad 132 with respect to the type 92 on the marking wheel 52 is effected by swinging the handle 108 (see FIGS. 2 and 4) until a kissing touch of the pad 132 with the face of the type 92 occurs. As the apparatus is being operated, the handle 108 may be operated to effect the desired transferal of ink to the type.

The axial position of the inking wheel 96 on the shaft 110 is maintained by suitable retaining rings removably secured to the inner surface of the arbor 112, the bearings 114 being confined therebetween. Suitable bearings and spacers extending from the shoulder 134 on the shaft 132 to the adjacent bearing 114 determines the axial position of the wheel 96, this position being in alignment with the marking wheel 52 such that the inking pad 132 engages the type 92 inside the two driving rims 94. With the axes of the two shafts 98 and 54 being parallel, a uniform kissing touch" of the rotating inking pad 132 with the rotating type face may be easily realized.

The particular apparatus herein disclosed is intended to be used in imprinting names, letters or codes on lumber as finally fabricated. Since this fabrication is oftentimes performed in cold winter temperatures, it is important that the temperature of the pad 132 be maintained at a level at which the ink transfers properly to the face of the type 92. This is achieved in the present invention by means of a heater assembly indicated generally by the number 136, this assembly being shown in detail in FIGS. 4, 8 and 11. Generally speaking, this assembly includes a flat plate 140 disposed in heatexchanging relationship with the side of inking wheel 96, the flat plate 140 being elevated in temperature which results in increasing the temperature of the inking wheel.

The side 120 of the inking wheel is provided with a plurality of axially extending, radially separated annular ribs coaxial with respect to the shaft extension 110. The heater assembly 136 includes a flat metal plate 140, shown as being circular in FIG. 8, also provided on one side with a plurality of radially spaced annular ribs 142 which are coaxially interleaved between in uniform spaced relation with the ribs 138 of the wheel side 120.

The plate is mounted on the shaft extension 110, but is held against rotation, this mounting including needle bearings 144 which permit eccentric adjustment of the shaft 98 as previously explained. In order to hold the plate 140 against rotation, an enlarged socket 146 is provided therein which receives the end 148 (FIG. 10) of the small pin projecting from the pivot pin 28 as shown. By means of the engagement between the walls of the socket 146 and the pin 148, the plate 140 is prevented from rotating relative to the arm 26.

The proper spaced relationship between the plate 140 and the wheel side 120 is maintained by means of the needle bearing assembly 144, a washer 150 (FIG. 4) abutting the side of the needle bearing assembly 144 as well as the side of the plate 140, a tubular spacer 152 on the shaft 110 engaged at the opposite ends thereof with the washer 150 and the adjacent bearing 114. The spacer 152 holds the plate 140 a fixed distance from the side 120. The fixed mounting of the bearings 114 with respect to the shaft 110 and the arbor 112 positively locates the inking wheel 96 such that the spaced relationship between the wheel and the heater assembly 136 is maintained.

More specifically, the wheel 96 is fixed in axial position on the shaft 110 by means of a bolt 154 threaded coaxially into the shaft 1 10 with the head thereof abutting against a washer 156 bearing against one side of the outboard bearing 114. By unscrewing the bolt 154, the wheel 96 may be withdrawn from the shaft 110 by merely grasping the hub 116 and withdrawing the inking wheel 96. This telescopes the bearings 114 attached to the wheel 96 from the shaft 110 thereby leaving the latter fully exposed.

The plate 140 on the side opposite the ribs 142 is provided with an integral enlargement 158 (see FIGS. 4 and 8), the socket 146 being provided in this enlargement 158. A radial bore 160 in this enlargement 158 receives an electrical heating probe 162 secured at its outer end to a metal housing 164 in turn secured to the plate 140 by means of screws 166. Inside the housing 164 is a thermal fuse 168, a thermostat and the wir ing for connecting these parts in series with the heating probe 162 which may be in the form used in electric stoves, soldering irons and the like. Suitable electric leads 172 emerge from the housing 164 for connection to external power circuitry.

The parts inside the housing 164 are embedded in a suitable solidified potting compound, epoxy being an example but preferably an insulating type plastic which is also heat conductive. By this means, the temperature of the fuse 168 and the thermostat 170 can be maintained substantially the same as the plate 140.

A second metal housing 174 (see FIG. 3) is mounted on the arm 26 by means of suitable screws 176, this housing 174 containing another thermostat 178 as shown. This thermostat 178 and the connecting wires inside the housing 174 are contained in potting compound the same as previously described such that the temperature of the thermostat 178 will be substantially the same as that of the ambient atmosphere.

The electrical circuitry including the various thermostats and fuse is shown in FIG. 11 as comprising a ground wire 180 and two power leads 182 and 184. This specific embodiment is designed to operate on 120 bolts at 60 cycles.

In series with the line 184 are the thermostats 170 and 178 and the thermal fuse 168. The heating element 162 is also connected in series with the line 182 and 184 as shown.

Preferably, the ribbed surface 142 is made reflective of infrared energy, such as by electroplating with a mirror like finish of chromium, nickel, anodized aluminum or the like. The ribbed surface 138 of the inking wheel 96 is made heat absorptive by finishing with a dull black paint, carbon or the like.

Assuming that the temperature of the inking pad 132 should not fall below 55F., the thermostats 170, 178 and thermal fuse 168 are arranged as follows. The thermostat 178 is provided with normally open contacts for temperatures above 55 such that no power is coupled to the heating element 162. When the ambient temperature drops below 55, the contacts of the thermostat 178 close. By the same token, the contacts in the thermostat 170 are normally closed at temperatures up to a predetermined temperature, such that if the temperature of the plate 140 exceeds this figure, the contacts will open thereby severing the power supply to the heating element 162. The thermal fuse 168 is set to self-destruct if the temperature exceeds a predetermined temperature, thereby permanently severing power to the heating element 162. In order to make the system operative, it would be necessary in this event to replace the thermal fuse 168.

The purpose of the thermal fuse 168 is to guard against excessive heat being generated by the heating element 162 which could lead to a fire. The same is true for the thermostat 170, but the latter is more for short term control and is effective to sever power to the heating element 162 so long as the contacts are open.

By maintaining the heater 140 stationary, no moving contacts or commutators are required for coupling electrical power to the heating element 162. This minimizes the chance of explosions or fire set off by electric sparks. Sparking is especially hazardous in atmospheres highly inflammable or explosive such as fine sawdust or volatile chemicals used as wood preservatives.

Heat transfer to the inking wheel 96 and more particularly to the pad 132 is efficiently accomplished by means of the ribbed surfaces 138 and 142, the electrical circuits operating to keep the temperature of the pad 132 at a proper value above 55, even though the ambient temperature may drop as slow as 35. The thermostat 178 is so constructed that when the contacts are closed because of ambient temperatures below 55, they open when the ambient temperature exceeds this figure. For the thermostat 170, while the contacts therein remain closed up to a predetermined temperature of, and open for higher temperatures, when the temperatures drop below this value, the contacts again close. If the thermal fuse 168 has not blown, then power would be reestablished to the heating element 162.

In adjusting the apparatus for operation, it is initially mounted adjacent to a conveyor line as illustrated in FIG. I wherein a stick of lumber normally referred to as a 2 X 4 is being ejected from a machine which performed the final planing and sizing operations. The apparatus of this invention is positioned to one side of an edge of this 2 X 4 for imprinting a legend thereon. The 2 X 4 is guided for movement along a straight line path in the direction of the arrow F so that a marking can be imprinted as indicated by the numeral 186. The apparatus is initially mounted by fastening the plate 14 to a rigid frame member in such position that the axes of the pins 54, 28 and 98 are vertical. When finally adjusted, the peripheries of the driving ribs 94 should be located about 1 inch inside the 2 X 4 edge to be printed such that without the 2 X 4 in place as shown in FIG. 1, the wheel 52 would be swung inwardly (to the right as viewed in FIG. 1) from the position there shown.

The nylon plug 36 of the adjustment screw 34 should project slightly, about one-quarter inch beyond the arm 26.

This adjustment may be achieved by loosening the screws 16, 22 to pivot the frame member 12 with respect to the pivot pin 20 and positioning the apparatus such that the type on the wheel 52 just touches the edge of the board when the imprint is to be made. While the board is removed from the planing machine, frame member 12 is swung inwardly to an extent that positions the periphery of the wheel 52 about 1 inch inside the plane normally occupied by the edge of the board to be imprinted. The screws 16, 22 are tightened onto the pivot support 20 to secure the frame member 12 against movement.

Next, with a 2 X 4 in place and the marking wheel 52 engaged with the edge thereof, the screw 38 is adjusted until about 10 pounds of force is exerted by the wheel 52 against the board.

Even though the emerging boards may be warped or have uneven surfaces, the wheel 52 can accommodate this unevenness and make a clear imprint on the board.

The screw 106 (FIG. 3) is adjusted to a position at which it engages the eccentric shaft 98 with some tightness but not so tight that the shaft 98 cannot be rotated manually by swinging the handle 108. The screw 106 being so adjusted, the handle 108 is swung to a position at which the periphery of the pad 132 just touches the type face 92. This engagement is shown in FIG. 3 and should be sufficient that the pad 132 will be rotated in response to the rotation of the wheel 52.

Referring to FIG. 1, as the 2 X 4 emerges from the machine, that is it moves toward the right, it engages the periphery of the wheel 52 and more particularly the driving ribs 94. This imparts rotation to the wheel 52. As the wheel rotates and the type 92 registers with the moving board, an imprint will be made on the board, the ribs 94 absorbing substantially all of the driving force required to rotate the wheel 52. This saves wear and tear on the type 92. Thus, for each rotation of the wheel 52, an imprint will be made on the board such that in one 8 foot length ofa 2 X 4, several imprints will be made in spaced relation thereon.

Because of the variation in surface regularity, it is necessary that the apparatus be capable of printing legibly thereon. This capability is built into the present apparatus by reason of the various adjustments 108, 106, 34 and 38. Thus, while the apparatus is being operated, these adjustments can be modified to obtain a clear imprint on the emerging board.

The electrical circuits for the heater 140 are so designed and arranged as to maintain the temperature of the inking pad 132 at about F. Other temperatures, of course, may be used depending upon the flow characteristics of the particular ink in the pad 132. Since boards emerge at high speed, in the rage of 500 lineal feet per minute, the marking wheel 52 will rotate at high velocity. Centrifugal force produced tends to throw the soft rubber type off the wheel; however, since the type 90 is in the form of a closed loop and is contained at the edges thereof, these high speeds can be tolerated without dislodging the type or interfering with the legibility of an imprint made.

A type loop of this character may in the first instance be used and secondly installed easily by reason of the particular structure of the wheel 52 which in one motion may be disassembled for installing a new type loop and by an opposite motion reassembled thereby quickly and reliably installing the type in place.

While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that description is made only by way of example and not as a limitation to the scope of the invention.

What is claimed is:

1. For use in marking apparatus, an inking-wheel device comprising a supporting wheel having an annular ink-retaining pad on the periphery thereof, and means for controlling the temperature of said pad, said means including heat-producing means in heat transfer relationship with said pad, said heat-producing means being held against movement, means for actuating and deactuating said heat-producing means when the temperature of said pad decreases and increases, respectively, from a predetermined temperature level, said heat-producing means including an electrical heater, said actuating and deactuating means including a thermostat connected to said heater, said pad being in heat transfer relationship with said wheel whereby heating said wheel results in heating said pad, said wheel being mounted for rotation with respect to said heater and said thermostat, a shaft mounting said wheel for rotation, said heat-producing means including a body of heat-dissipating material mounted adjacent to one side of said wheel in heat-transferring relationship therewith, said body carrying said heater, said body being mounted on said shaft but held against rotation, the side of said wheel facing said body being provided with a plurality of raised heat-transfer portions, said body having on its side facing said wheel raised radiator portions juxtaposed with respect to the heat-transfer portions and arranged so as to clear each other during rotation of said wheel.

2. The device of claim 1 in which the heat-transfer and radiator portions are in the form of annular ribs radially spaced apart and coaxial with respect to the axis of wheel rotation, the ribs of said wheel being radially and axially spaced from but interleaved with the ribs of said body.

3. The device of claim 2 in which the ribs on said wheel define a flat side and said body is in the form of a flat plate, a frame member supporting said shaft for rotation with respect thereto, the portion of said shaft supported on said frame member being eccentric with respect to the portion mounting said wheel and body, and a means on said frame member for holding said body against rotation but permitting movement thereof due to rotational movement of said shaft in said memher.

4. The device of claim 3 in which the last-mentioned means includes a socket which receives for relative movement therein a projection, the socket being one of said frame member and said body and the projection being on the other.

5. The device ofclaim 4 in which said heat-producing means includes electrical circuitry comprising an ambient temperature-sensing thermostat fixedly mounted relative to said frame member but spaced sufficiently from said body to be insensitive to the temperature thereof, a heat sensitive circuit-breaking device on said body in heat-transferring relation therewith, said lastmentioned thermostat and said circuit-breaking device being connected in series in an electrical power circuit connected to said heater, said thermostat having contacts that are normally open above a predetermined ambient temperature but which close for temperatures therebelow, said circuit-breaking device being normally conductive for heater temperatures below a predetermined temperature but non-conductive for temperatures thereabove.

6. The device of claim 5 including a second thermostat in series with said circuit-breaking device, said second thermostat being mounted on said body in heattransferring relationship and having contacts normally closed for temperatures below a predetermined level but open for temperatures thereabove.

7. For use in marking apparatus, a marking wheel comprising a rim portion, a closed loop of rubber type removably telescopically fitted onto the exterior thereof, said loop having opposite circumferential edges, means for securing said loop at said edges to said rim portion against radially outward dislocation during rotation of said marking wheel, said securing means including two parts removably secured together, said wheel including two wheel sections removably assembled together, said two parts being carried by said two wheel sections, respectively, one of said wheel sections including an arbor and the other a hub telescopically fitted onto said arbor, detent means releasably securing said wheel sections against axial separation, means releasably securing said two wheel sections against relative rotation, said rim portion includes a cylindrical element on one of said wheel sections engaged by said type loop, and said two parts of said securing means include two axially spaced facing annular grooves, respectively, which receive in close fitting relation the opposite edges of said type loop, said means for securing said two wheel sections against relative rotation includes an axially extending groove in one of said hub and arbor, a projection slidably received by said groove and carried by the other of said hub and arbor.

8. For use in marking apparatus, an inking-wheel device comprising a supporting wheel having an annular ink-retaining pad on the periphery thereof, and means for controlling the temperature of said pad, said means including heat-producing means in heat transfer relationship with said pad, said heat-producing means being held against movement, means for actuating and deactuating said heat-producing means when the temperature of said pad decreases and increases, respectively, from a predetermined temperature level, said heat-producing means including an electrical heater, said actuating and deactuating means including a thermostat connected to said heater, said pad being in heat transfer relationship with said wheel whereby heating said wheel results in heating said pad, said wheel being mounted for rotation with respect to said heater and said thermostat, a shaft mounting said wheel for rotation, said heat-producing means including a body of heat-dissipating material mounted adjacent to one side of said wheel in heat-transferring relationship therewith, said body carrying said heater, said body having a side spaced from and substantially coextensive with the side of said wheel, said sides being substantially parallel such that heat radiates from said body to said wheel, and means mounting and holding said body against rotation whereby said wheel may rotate clear of said body, being heated by radiation therefrom. 

1. For use in marking apparatus, an inking-wheel device comprising a supporting wheel having an annular ink-retaining pad on the periphery thereof, and means for controlling the temperature of said pad, said means including heat-producing means in heat transfer relationship with said pad, said heatproducing means being held against movement, means for actuating and deactuating said heat-producing means when the temperature of said pad decreases and increases, respectively, from a predetermined temperature level, said heat-producing means including an electrical heater, said actuating and deactuating means including a thermostat connected to said heater, said pad being in heat transfer relationship with said wheel whereby heating said wheel results in heating said pad, said wheel being mounted for rotation with respect to said heater and said thermostat, a shaft mounting said wheel for rotation, said heatproducing means including a body of heat-dissipating material mounted adjacent to one side of said wheel in heat-transferring relationship therewith, said body carrying said heater, said body being mounted on said shaft but held against rotation, the side of said wheel facing said body being provided with a plurality of raised heat-transfer portions, said body having on its side facing said wheel raised radiator portions juxtaposed with respect to the heat-transfer portions and arranged so as to clear each other during rotation of said wheel.
 2. The device of claim 1 in which the heat-transfer and radiator portions are in the form of annular ribs radially spaced apart and coaxial with respect to the axis of wheel rotation, the ribs of said wheel being radially and axially spaced from but interleaved with the ribs of said body.
 3. The device of claim 2 in which the ribs on said wheel define a flat side and said body is in the form of a flat plate, a frame member supporting said shaft for rotation with respect thereto, the portion of said shaft supported on said frame member being eccentric with respect to the portion mounting said wheel and body, and a means on said frAme member for holding said body against rotation but permitting movement thereof due to rotational movement of said shaft in said member.
 4. The device of claim 3 in which the last-mentioned means includes a socket which receives for relative movement therein a projection, the socket being one of said frame member and said body and the projection being on the other.
 5. The device of claim 4 in which said heat-producing means includes electrical circuitry comprising an ambient temperature-sensing thermostat fixedly mounted relative to said frame member but spaced sufficiently from said body to be insensitive to the temperature thereof, a heat sensitive circuit-breaking device on said body in heat-transferring relation therewith, said last-mentioned thermostat and said circuit-breaking device being connected in series in an electrical power circuit connected to said heater, said thermostat having contacts that are normally open above a predetermined ambient temperature but which close for temperatures therebelow, said circuit-breaking device being normally conductive for heater temperatures below a predetermined temperature but non-conductive for temperatures thereabove.
 6. The device of claim 5 including a second thermostat in series with said circuit-breaking device, said second thermostat being mounted on said body in heat-transferring relationship and having contacts normally closed for temperatures below a predetermined level but open for temperatures thereabove.
 7. For use in marking apparatus, a marking wheel comprising a rim portion, a closed loop of rubber type removably telescopically fitted onto the exterior thereof, said loop having opposite circumferential edges, means for securing said loop at said edges to said rim portion against radially outward dislocation during rotation of said marking wheel, said securing means including two parts removably secured together, said wheel including two wheel sections removably assembled together, said two parts being carried by said two wheel sections, respectively, one of said wheel sections including an arbor and the other a hub telescopically fitted onto said arbor, detent means releasably securing said wheel sections against axial separation, means releasably securing said two wheel sections against relative rotation, said rim portion includes a cylindrical element on one of said wheel sections engaged by said type loop, and said two parts of said securing means include two axially spaced facing annular grooves, respectively, which receive in close fitting relation the opposite edges of said type loop, said means for securing said two wheel sections against relative rotation includes an axially extending groove in one of said hub and arbor, a projection slidably received by said groove and carried by the other of said hub and arbor.
 8. For use in marking apparatus, an inking-wheel device comprising a supporting wheel having an annular ink-retaining pad on the periphery thereof, and means for controlling the temperature of said pad, said means including heat-producing means in heat transfer relationship with said pad, said heat-producing means being held against movement, means for actuating and deactuating said heat-producing means when the temperature of said pad decreases and increases, respectively, from a predetermined temperature level, said heat-producing means including an electrical heater, said actuating and deactuating means including a thermostat connected to said heater, said pad being in heat transfer relationship with said wheel whereby heating said wheel results in heating said pad, said wheel being mounted for rotation with respect to said heater and said thermostat, a shaft mounting said wheel for rotation, said heat-producing means including a body of heat-dissipating material mounted adjacent to one side of said wheel in heat-transferring relationship therewith, said body carrying said heater, said body having a side spaced from and substantially coextensive with the side of said wheel, said sIdes being substantially parallel such that heat radiates from said body to said wheel, and means mounting and holding said body against rotation whereby said wheel may rotate clear of said body, being heated by radiation therefrom. 